Electrically held three position cutout switch

ABSTRACT

A push button switch includes an armature pivotally mounted on a pole piece. The armature is biased by a spring against the magnetic force of a coil on the pole piece. A push button pivots about a second axis parallel to the armature pivot axis and includes an active projection that engages a cam surface on the armature. The push button may be manually operated to drive the armature toward or away from the coil. A positive detent is defined in the cam surface to provide positive disengagement of the armature from the coil upon appropriate movement of the push button. The cam surface also provides a momentary action by the push button when driving the armature toward the coil.

United States Patent [191 Collette [451 Oct. 15,1974

1 1 ELECTRICALLY HELD THREE POSITION CUTOUT SWITCH [75] Inventor: Richard L. Collette, Hoffman Estates, 111.

[73] Assignee: Guardian Electric Manufacturing Company, Chicago, Ill.

[22] Filed: Jan. 4, I974 [2]] Appl. No.: 431,142

Primary Examiner-G. Harris Attorney, Agent, or FirmMo1inare, Allegretti, Newitt & Witcoff [57] ABSTRACT A push button switch includes an armature pivotally mounted on a pole piece. The armature is biased by a spring against the magnetic force of a coil on the pole piece. A push button pivots about a second axis parallel to the armature pivot axis and includes an active projection that engages a cam surface on the armature. The push button may be manually operated to drive the armature toward or away from the coil. A positive detent is defined in the cam surface to provide positive disengagement of the armature from the coil upon appropriate movement of the push button. The cam surface also provides a momentary action by the push button when driving the armature toward the coil.

10 Claims, 5 Drawing Figures STOP SHEET 2 BF 2 h. N M

T 3 E m 1 M a T MW 2 w A mm PATENTEDHC? 151974 SENSORS AND MO/V/ TORS ELECTRICALLY HELD THREE POSITION CUTOUT SWITCH BACKGROUND OF THE INVENTION The present invention relates to a push button switch device and, more particularly, to a switch device including the feature of a safety interlock.

During a power failure or power loss, it is often necessary to make sure that electrically run equipment will be rendered inoperative pending correction of a fault and positive manual restart. For this reason, a safety interlock mechanism is normally required in association with the switching mechanism controlling the equipment. Such a safety mechanism will preferably automatically disengage the power supply to the switch controlled equipment whenever current supply is terminated or drops below a critical level.

Such switching equipment preferably also includes a feature permitting positive manual operation and disengagement of a circuit. Such a switch construction should have a simple, compact design with a minimum number of moving parts and, quite importantly, improved reliability. It is with these criteria in mind that the present invention was conceived.

SUMMARY OF THE INVENTION In a principal aspect, the present invention comprises a pivotally mounted armature cooperative with a current sensitive coil. The armature is normally biased away from the coil. A pivotal push button is mounted for cooperation with the armature to pivot the armature toward or away from the coil. This is accomplished by a cooperative cam surface and cam follower associated with the push button and the armature.

Thus, it is an object of the present invention to provide an improved switch mechanism.

It is a further object of the present invention to provide an improved switch mechanism which may be maintained in a circuit so long as adequate current is provided to a coil to thereby retain an armature in a circuit closed position.

Another object of the present invention is to provide a switch device responsive to a push button to position the switching mechanism and an armature of the device in a closed circuit position, maintenance of the switch in the closed circuit position being dependent upon mechanism and structure other than the push button.

Still another object of the present invention is to provide a push button switch device including a push button operative to positively move and maintain the switch in an open circuit condition.

One further object of the present invention is to provide a push button switch with a pivoting push button cooperative with a pivoting armature, the armature, in turn, being operative to drive contacts and effect circuit switching.

These and other objects, advantages and features of the invention will be set forth in the detailed description which follows.

BRIEF DESCRIPTION OF THE DRAWING In the detailed description which follows, reference will be made to the drawing comprised of the following Figures:

FIG. 1 is a cross-sectional view of the switch of the present invention in an open circuit condition;

FIG. 2 is a cross-sectional view similar to FIG. 1 wherein the switch is in a closed circuit condition;

FIG. 3 is a cross-sectional view similar to FIG. 1 wherein the switch has been operated to position and maintain the device in an open circuit condition;

FIG. 4 is an exploded perspective view illustrating the separate components of the improved switch of the present invention; and

FIG. 5 is a typical circuit diagram incorporating the switch of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the Figures, the switch of the present invention is shown enclosed in a housing 10. Positioned within the housing is a mounting bracket and pole piece 12 having a coil 14 mounted thereon. As depicted, the axis of the coil 14 is vertical and is parallel to a vertical run 16 on the pole piece 12. The vertical run 16 of pole piece 12 terminates at its upper end as a pivot 18.

An armature 20 is mounted for pivotal motion on the pivot 18 for pivotal movement about a horizontal axis. The armature 20 is a substantially planar member and extends in opposite directions from the pivot 18. The armature 20 includes a loop 22 to which a spring 24 is attached. The opposite end of spring 24 engages a tab 26 extending from the pole piece 12. The armature 20 is biased about the pivot 18 by spring 24 in a clockwise manner.

One end 21 of the armature 20 is adjacent the end of coil 14 as illustrated in FIG. 2 and is maintained against the coil 14 whenever current is passed through the coil 14 coincident with translation of armature 20 against the biasing force of spring 24 to move the end of the armature 20 adjacent the coil 14. The opposite or outside end 23 of the armature 20 is adapted to engage and move contact driving members 28 and 30.

A cam member 32 is attached to the top surface of the armature 20. The cam member 32 is cooperative with a cam follower or cam projection 34 extending from a push button 36. The push button 36 is mounted in housing 10 to pivot about a second horizontal axis 38. The axis 38 is substantially parallel to the axis of pivot 18. The axis of pivot 18 and axis 38 define a substantially vertical plane through the switch housing 10.

The cam member 32 includes a cam surface 33 with a middle detent 40 which is substantially in the plane defined by the pivot 18 and axis 38. As cam surface 33 extends outwardly from the middle detent 40 along sides 21 and 23, it also becomes increasingly distant from the plane defined by armature 20. A stop detent 42 is also defined in surface 33 adjacent side 23. However, the cam surface 33 is smooth and inclined downwardly toward the middle detent 40 adjacent side 21 to provide a momentary switch action.

Movement of the push button 36 in a clockwise sense about axis 38 imparts a counterclockwise motion to the armature 20 causing the projection 34 to ride up surface 33 to provide a momentary switch action. If the switch contacts are appropriately arranged, this will effect closing a circuit including activation of the coil 14. The armature 20 will thus be held in a closed circuit position as illustrated in FIG. 2.

To open the circuit, the push button 36 may be moved in the counterclockwise sense, thereby causing projection 34 to engage detent 42. This causes the armature to rotate in the clockwise direction out of engagement with the coil 14 to the position illustrated in FIG. 3.

Referring now to FIG. 5, there is shown a typical circuit diagram incorporating, schematically, a switch of the present invention. It will be noted that upon actuation of the push button 36, the contact drive member 28 is released and control drive member 30 is engaged thereby causing contacts 46 and 48 and contacts 52 and 54 to close, thus closing sensing and control circuit 50, as well as the main circuit 56 through load 58. The coil 14 is in series with various sensors and other circuit safety mechanisms of circuit 50. So long as sufficient control voltage or current is maintained in circuit 50, the coil 14 holds the armature 20 in closed circuit position. In the event of a power failure or other current loss or discontinuance, the coil 14 is de-energized thereby releasing the armature 20 and automatically preventing re-establishment of the circuit pending affirmative manual operation of the push button 36.

The preferred embodiment of the switch of the present invention has been described in combination with typical circuits. Variations are within the scope of the invention. For example, the cam surface 33 and the surface 32 may be defined on button 36 with projection 34 being attached to armature 20. Additionally, the armature 20 may be operative to open and close contacts in a sequence different from that disclosed. Therefore, the improved switch arrangement of the present invention is to be limited only by the following claims and their equivalents.

What is claimed is:

1. An improved switch device comprising, in combination:

a coil;

a biased armature pivotally mounted to pivot about a first axis with respect to said coil for movement toward and away from said coil in response to current and lack of current respectively through said coil; and

push button means pivotally mounted about a second axis parallel to the first axis, one of said push button means and said armature having a cooperative cam and the other having a cam follower projection, said cam and cam follower projection coacting to drive said armature about the first axis in a sense opposite the operated sense of said push button means.

2. The switch device of claim 1 wherein said cam surface includesa first detent position, said cam and follower projection operative to drive said armature in the same sense as the biasing means associated with said armature and engage said first detent to retain the armature.

3. The switch device of claim 1 wherein said cam surface includes a non-detent portion, said cam surface and follower projection operative to engage on the non-detent portion and pivot said armature in the opposite sense from the biasing for said armature with a momentary switch action.

4. The switch device of claim 1 including circuit means for providing current through said coil to retain said armature in the position said armature is translated by cooperative action of said cam and follower projection.

5. The switch device of claim 1 wherein said cam is attached to said armature to define a cam surface.

6. The switch device of claim 1 wherein said cam includes a middle detent position substantially on a plane defined by the first axis and second axis.

7. The switch of claim 1 including contact switch members engageable by said armature to effect making and breaking circuit paths through contacts.

8. An improved switch device including a current sensitive switch release mechanism comprising, in combination:

a coil mounted on a pole piece, said pole piece including a pivotal mount; an armature pivotally mounted on said pole piece; biasing means for normally biasing said armature in a direction away from said coil;

a cam mounted on said armature, said cam including a cam surface; and

push button means mounted for pivotal movement about another axis parallel to the pivot axis of said armature, said push button means including a projection engaging said cam surface to provide the armature with a neutral position, a positive stop position and a momentary switch position, said m0- mentary position being in a sense opposite the direction of rotation the biasing means provides to said armature.

9. The switch of claim 8 including circuit means in series with said coil whereby upon actuation of said switch device to the momentary position activates said coil to hold said armature in the momentary position upon release of said push button means.

10. The switch of claim 8 including contact driving members engageable by said armature to effect making and breaking circuit paths through contacts. 

1. An improved switch device comprising, in combination: a coil; a biased armature pivotally mounted to pivot about a first axis with respect to said coil for movement toward and away from said coil in response to current and lack of current respectively through said coil; and push button means pivotally mounted about a second axis parallel to the first axis, one of said push button means and said armature having a cooperative cam and the other having a cam follower projection, said cam and cam follower projection coacting to drive said armature about the first axis in a sense opposite the operated sense of said push button means.
 2. The switch device of claim 1 wherein said cam surface includes a first detent position, said cam and follower projection operative to drive said armature in the same sense as the biasing means associated with said armature and engage said first detent to retain the armature.
 3. The switch device of claim 1 wherein said cam surface includes a non-detent portion, said cam surface and follower projection operative to engage on the non-detent portion and pivot said armature in the opposite sense from the biasing for said armature with a momentary switch action.
 4. The switch device of claim 1 including circuit means for providing current through said coil to retain said armature in the position said armature is translated by cooperative action of said cam and follower projection.
 5. The switch device of claim 1 wherein said cam is attached to said armature to define a cam surface.
 6. The switch device of claim 1 wherein said cam includes a middle detent position substantially on a plane defined by the first axis and second axis.
 7. The switch of claim 1 including contact switch members engageable by said armature to effect making and breaking circuit paths through contacts.
 8. An improved switch device including a current sensitive switch release mechanism comprising, in combination: a coil mounted on a pole piece, said pole piece including a pivotal mount; an armature pivotally mounted on said pole piece; biasing means for normally biasing said armature in a direction away from said coil; a cam mounted on said armature, said cam including a cam surface; and push button means mounted for pivotal movement about another axis parallel to the pivot axis of said armature, said push button means including a projection engaging said cam surface to provide the armature with a neutral position, a positive stop position and a momentary switch position, said momentary position being in a sense opposite the direction of rotation the biasing means provides to said armature.
 9. The switch of claim 8 including circuit means in series with said coil whereby upon actuation of said switch device to the momentAry position activates said coil to hold said armature in the momentary position upon release of said push button means.
 10. The switch of claim 8 including contact driving members engageable by said armature to effect making and breaking circuit paths through contacts. 